Never use the pkg_resources metadata backend on python 3.13+

news/13010.removal.rst

@@ -0,0 +1,2 @@
+On python 3.13+, the ``pkg_resources`` metadata backend is not used anymore,
+and pip does not attempt to detect installed ``.egg`` distributions.

src/pip/_internal/metadata/__init__.py

@@ -30,16 +30,19 @@ def _should_use_importlib_metadata() -> bool:
  """Whether to use the ``importlib.metadata`` or ``pkg_resources`` backend.
 
  By default, pip uses ``importlib.metadata`` on Python 3.11+, and
- ``pkg_resourcess`` otherwise. This can be overridden by a couple of ways:
+ ``pkg_resources`` otherwise. Up to Python 3.12, This can be
+ overridden by a couple of ways:
 
  * If environment variable ``_PIP_USE_IMPORTLIB_METADATA`` is set, it
- dictates whether ``importlib.metadata`` is used, regardless of Python
-  version.
- * On Python 3.11+, Python distributors can patch ``importlib.metadata``
- to add a global constant ``_PIP_USE_IMPORTLIB_METADATA = False``. This
- makes pip use ``pkg_resources`` (unless the user set the aforementioned
- environment variable to *True*).
+ dictates whether ``importlib.metadata`` is used, for Python <3.13.
+ * On Python 3.11 and 3.12, Python distributors can patch
+  ``importlib.metadata`` to add a global constant
+ ``_PIP_USE_IMPORTLIB_METADATA = False``. This makes pip use
+ ``pkg_resources`` (unless the user set the aforementioned environment
+ variable to *True*).
  """
+ if sys.version_info >= (3, 13):
+ return True
  with contextlib.suppress(KeyError, ValueError):
  return bool(strtobool(os.environ["_PIP_USE_IMPORTLIB_METADATA"]))
  if sys.version_info < (3, 11):

src/pip/_internal/metadata/importlib/_envs.py

@@ -173,9 +173,10 @@ def _iter_distributions(self) -> Iterator[BaseDistribution]:
  finder = _DistributionFinder()
  for location in self._paths:
  yield from finder.find(location)
- for dist in finder.find_eggs(location):
- _emit_egg_deprecation(dist.location)
- yield dist
+ if sys.version_info < (3, 13):
+ for dist in finder.find_eggs(location):
+ _emit_egg_deprecation(dist.location)
+ yield dist
  # This must go last because that's how pkg_resources tie-breaks.
  yield from finder.find_linked(location)
 

tests/functional/test_uninstall.py

@@ -628,6 +628,10 @@ def test_uninstall_with_symlink(
  assert symlink_target.stat().st_mode == st_mode
 
 
+@pytest.mark.skipif(
+ "sys.version_info >= (3, 13)",
+ reason="Uninstall of .egg distributions not supported in Python 3.13+",
+)
 def test_uninstall_setuptools_develop_install(
  script: PipTestEnvironment, data: TestData
 ) -> None: